10D and exposure time greater than 30 seconds.... any problems?

I have a remote timer cable release for the 10D. Suddenly, I can now take
exposures longer than 30 seconds. I can let an exposure run for hours if I
desire. My questions are as follows:::::::::::

1. Can the sensor be damaged by using a longer exposure......... what of 5
min, 20 min, 30 minutes, etc?

2. As you go for longer exposure times, what type of distortion or
technical limit will I run into with digital that I would not run into with
film?

3. Anything I should know before taking longer (for low light shots)
exposure shots with my 10D and the remote timer switch?

Jimmy

 

Hot pixels or stuck pixels (meaning pixels that are improperly activating a
particular color, even though it hasn't been exposed to it) will become
brightly visible...meaning you will have to remove them in post-processing.
Actually though, the 10D (and Canon's other CMOS sensor DSLRs) are arguably
the best digitals when it comes to handling long exposures well. I visited
Carlsbad Caverns last Spring, taking many many long exposures with with my
10D. Many of them were over a minute, and the results were amazingly clean
in terms of noise and stuck/hot pixels.

 

For very long exposures, make sure the battery is freshly charged.
Even better, consider buying and using the mains adapter. That way you won't
have the battery die partway through an exposure.

 

No. Think about the instructions for cleaning sensor.

Noise. If you get a bad pixel or two, then Paintshop is your friend.

Test away with known targets first. Try painting a room with flashlight or
yourself into the picture. You can have a lot of fun with long exposures
and digital makes it instant gratification. Have a fine and amusing time.

-paul

 

Depending if you hold the sensor straight into the full moon or not.
I doubt there are any problems taking shots in the dark.

My 10D had dead and hot pixels straight of the box.
The next one was better....

Cheers

 

Should be OK, just try not to do this ...

http://ireid.home.cern.ch/ireid/images/JuraSunset.wmv (3.7 Mb)
(Nikon CCD)

 

Irrelevant - the sensor is not turned on during cleaning.

 

The sensor will collect charge whenever there is light falling on it. The
only way to stop it is to keep it in the dark.

 

Take a dark frame (same duration) so you'll be able to remove hot pixels
more easily.

 

Wow! That's a painful demonstration.

 

You can take long exposures with the 10D.
Here are noise tests as a function of temperature for
exposures as long as 6 minutes:

http://clarkvision.com/astro/canon-10d-signal-to-noise

In the amateur astronomy world, people are taking multiple
exposures in raw mode and adding them together to produce
stunning low light images that were simply impossible
with film. For example, see:

http://clarkvision.com/galleries/gallery.astrophoto-1

A google search will probably reveal many amateur
astronomer web sites of people using the 10D and
producing far better results than I have. One trick is
combining images properly. People are using a program
called ImagesPlus (a google search should find it).
It aligns and processes 16-bit images and has filters
far beyond photoshop (I have no affiliation). It also
does batch raw conversions of canon 10D (and other
DSLR) camera files.

Multiple exposures averaged together reduces noise and
can produce a smoother image than with film.

Roger
http://clarkvision.com